Die casting machine



June 5, c P 1,9615942 DIE CASTING MACHINE Filed July 26, 1930 4Sheets-Sheet l BY 0a AT ORNEYS.

June 5, 1934.

C. PACK DIE CASTING MACHINE Filed July 26, 1930 4 Sheets-Sheet 4 IN V ENTOR.

*a ATTORNEYS.

Patented June 5, 1934 DIE CASTING MACHINE Charles Pack, Jackson Heights,N. Y.

Application July 26, 1930, Serial No. 470,859

28 Claims.

This invention relates to die casting, and more particularly to a diecasting machine adapted for the casting of any metal under any desiredhigh pressure.

In my copending application Ser. No. 417,849 filed January 2, 1930, Ihave disclosed and claimed a novel method and machine for ,die casting.

In accordance with the said disclosure the die is provided with a cup orreceptacle for molten metal in addition to the mold impression. This cupis filled manually with molten metal from a separately heated crucible,after which the die is closed, and a plunger, smaller in diameter thanthe receptacle, is forced into-the receptacle in order to displace thecenter portion of the metal therefrom into the mold. The plunger is thenretracted, the die opened, and the casting and cup-shaped gate ejected.

This method makes it possible to cast any metal, even those of highmelting point, at high pressures. The difliculties of close .tolerancesare avoided, the machine remains at a low temperature, and chilling ofmetal around the cup I is provided for, thereby avoiding abrasion andchanged at will.

The object of the present invention, generally, is to improvethediecasting machine disclosed in my prior application while retaining allof the foregoing advantages of the die casting meth- 0d and machine setforth above.

In my prior machine the die and the plunger were both operated byconcentrically arranged pistons and cylinders, and this resulted in themachine having considerable height. It' also necessitated the use of acomplex arrangement of bushings to prevent oil leakage, and made theplunger'relatively inaccessible for the provision of water cooling. Oneobject of the present invention is to overcome these difiiculties and toprovide mechanism for operating the die, and additional mechanism foroperating the plunger, which will be separately, independently, andadvantageously located with a view to reducing the height of the machineand simplifying and improving the accessibility of the individualmechanisms.

In preferred form the machine employs fixed and movable plates on whichthe die portions are mounted. To simplify the frame of the machine andto keep the height of the cup, which must be filled with molten metalfrom an appropriate ladle, constant, it is preferable-that the fixedplate be the lower plate. Inasmuch as the plunger and die operatingmechanisms are preferably located on opposite sides of the fixed andmovable plates, it then becomes of advantage to 10-- cate the plunger onbottom, or beneath the fixed plate, and to force it upwardly into thecup for the casting operation. This, however, introduces difficulty dueto the formation of a fin at the bottom of the cup which tends to wearthe plungerwith cumulatively bad effect, inasmuch as it may not beremoved when the cup-shaped gate is ejected after each castingoperation. Accordingly, further objects of my invention are to preventthe formation of such a fin, and, in the event of its formation, toinsure ejection thereof with the gate. To this end, a tapered approachbe-. tween the bottom of the cup and the side walls of the plunger isprovided when the cup is being filled with metal, so that preliminarychilling of the metal later opposes the formation of a fin. When thegate is who ejected, the plunger'is retracted a substantial distancebelow the bottom of the receptacle, thereby clearing and releasing thefin so that it is readily ejected with the balance of the metal left inthe receptacle. The plunger is then raised to an intermediate positionnear or slightly above the bottom of the receptacle preparatory tofilling the receptacle with a new charge of molten metal. In otherwords, the plunger is effectively operated in three positions ormovements instead of the customary two.

A further object of the invention is to provide hydraulically operatedmeans and relatively simple valve mechanism therefor, for obtaining thedesired upward, downward, and intermediate positions of the plunger. Forthis purpose, 'the plunger is directly connected to a piston arranged toreciprocate between the upward and downward positions. In addition, amovable stop is provided for moving the piston and plunger from thedownward to the desired intermediate position, and this stop ispreferably actuated by a small auxiliary piston and cylinder locatedbeneath the head of the main cylinder and subjected to continuouspressure which is overcome, when necessary, by the main piston. I

The separable die portions are preferably operated by hydraulicmeanstaking the form of a cylinder and piston located on top of an upperfixed plate spaced frohrth lower fixed plate by pillars. A movable platelocated between the upper and lower fixed plates carries the upper dieportion and is moved by the piston. In accordance with further objectsof the invention, this mechanism is arranged to necessitate the use ofonly a single valve, and this valve is so interconnected with the valvescontrolling the operation of the plunger as to insure closing of the dieprior to the casting movement of the plunger, and movement of theplunger to the intermediate position prior to closing of the die.

The necessary opening or separation of the portions of the die isdependent upon factors which are more or less independent of 'theover-all dimension of the die including the die box with its ejector andcore plates. When a relatively extreme change in size of the die must beaccommodated, it is desirable that the spacing between the mean positionof the movable plate and the lower fixed plate be variable, and inaccordance with another object of the present invention this change isprovided for by making the pillars which determine the spacing betweenthe upper and lower fixed plates replaceable, so that pillars of greaterlength may-be substituted when necessary.

When the height of the die is.relatively small, the opening of the diemay be greater than necessary if the piston operating the same ispermitted to rise to the top of its stroke. This is waste.- ful of time'and power, and accordingly it is a further object of this invention tomake it possible to limit the opening stroke of the die as desired, andvariable or replaceable stop means are provided for this purpose.

The die ordinarily consists of an ejector die and a cover die. Theejector die is provided with an ejector plate and ordinarily also with acore plate, and a further object of this invention is to arrange for theoperation of these plates. This may be more readily accomplished whenthe ejector die is made the movable portion of the die, and accordinglyin the present machine the die is inverted so that the ejector die is ontop of the cover die. cover die, and inasmuch as the cover die isusually small in height relative to the ejector die, this possesses theadditional advantages of reducing the elevation of the cup andpermitting the elevation thereof to remain constant. Suitable levermechanism is provided to interconnect the fixed frame of the machine,the movable die, and thecore plate, to cause the core plate to be movedtoward the cover die when the die is closed and away from the cover diewhen the die is opened, thereby providing for retraction of the cores,which lengthens their wear and facilitates ejection of the casting. Theupward movement of the ejector plate with the ,ejector die is arrestednear the end of the stroke, causing the ejector pins on the ejectorplate to eject the casting from the ejector die.

It frequently is necessary to employ side pulled cores. Wheneverpossible, these are located in the ejector die, and a further object ofthis invention is to provide for automatic operation of such a sidepulled core located in the ejector die. For this purpose a fixed memberhaving inclined bearingsurfaces, preferably in the form of a slot,

is attached to-the frame of the machine and cooperates with a followerriding in the slot and attached to the core. The follower is moved inthe slot when the ejector die is raised or lowered, and the inclinationof the slot is made proper to cause insertion of the core when the dieis closed and retraction of the core. when the die is opened.

Occasionally the nature of the casting is such that it is necessary toemploy a side pulled core in the cover die. Such a core must normally bepulled manually, but this isundesirable because the core must be pulledbefore the die is-opened, and a single misstep will ruin the casting andmay ruin the entire die. Accordingly, a further object of my inventionresides in the provision of power means for automatically pulling a sidepulled core in the cover die. This is accomplished by attaching adetachable hydraulically operated piston and cylinder mechanism to theframe The cup is then located in the of the machine adjacent the corefor operating the core. The piping to this cylinder is so arranged thatno additional valves other than those ordinarily employed in the machineare necessary, and yet retraction of the core prior to opening of thedie, and insertion of the core prior to the operating stroke of theplunger are assured.

Further objects of the present invention center about the manufacture ofrelatively large die castings. When making small castings the cup orreceptacle for molten metal is located at the center of the die, and themold impressions for the articles to be cast, are distributed around thecenter gate. When making a large casting, the cup may itself be in theway of the desired mold impression, and it is a further object of thepresent invention to care for such cases and to make it possible to movethe cup, the plunger, and the operating mechanism therefor toward oneside or the other of the die sothat an offset gate may be provided. Itmay incidentally be pointed out that the possibility of obtaining thisdesired adjustment constitutes another important advantage of theseparated mechanisms for operating the plunger and the die employed inthe present machine, in contrast with the concentric combined mechanismemployed in my prior machine.

At times it is necessary'to make castings which are even larger thanthose which may be accommodated by the expedient just described. Whenmaking relatively long, and slender castings, it

is necessary not only that the die beaccommodated by the machine, butalso that metal be fed to the extremities of the die impression beforeit has time to chill. To provide for the successful manufacture of suchcastings is still another object of my invention, and for this purpose aplurality of receptacles for molten metal are employed in communicationwith a single mold, and a plurality of plungers are simultaneously movedinto the receptacles in order to displace metal therefrom into the mold.This desired arrangement is preferably provided for withoutnecessitating a special casting machine, by the relatively simpleexpedient of so designing the individual casting machines that two ormore may be assembled at will and rigidly locked together when it isnecessary to make a large casting. The similar elements of the machinemay be piped together 1 in parallel, or the valve mechanisms thereof maybe geared to operate together in order to insure simultaneous operationof the component machines. Any slight differences in this respect areamply taken care of by the fact that it is a single rigid die which isbolted to the fixed and movable plates of the several machines.

To the accomplishment of the foregoing and such other objects as willhereinafter appear, my invention consists in the die casting machineelements and their relation one to the other as hereinafter are moreparticularly described in the specification and sought to be defined inthe claims. The specification is accompanied by drawings in which:

Fig. l is a partially sectioned side elevation of a die casting machineembodying my invention;

Fig. 2 is a horizontal section taken between the separable die portions;

Fig. 3 is a similar section taken through a machine having a differentdie, necessitating a side pulled core in the cover die; 1

Fig. 4 is an elevation showing the core plate mechanism;

Fig. 5 is a partially sectioned elevation through the ejector diemechanism; 1 I

Fig. 6 is an enlarged section through the cup and plunger inintermediate position;

Fig. 7 is a similar section through the cup and plunger in castingposition; i I Fig. 8 is a side elevation of a multiple machine for themanufacture of large castings; and

Fig. 9 is a side elevation of the valve mechanism.

Referring to the drawings and more particularly' to Fig. 1 thereof,the.present die casting machine comprises separable die portions A andB/a cup or receptacle formolten metal C, and a plunger D smaller indiameter than the receptacle for displacing metal therefrom into a moldimpression in the die. The plunger D is operated by appropriatemechanism E, while the movable die portion B is operated by appropriatemechanism F. The mechanisms E and F are septher be noted that it ispreferred to make the lower die portion A the fixed part' of the die,although this necessitates that the plunger D be located at the bottomof the machine and operated upwardly into the receptacle C.

The mechanism E is preferably hydraulically operated and comprises amain cylinder 2, and a piston 4 reciprocable therein and actuating apiston rod 6. Plunger'D is rigidly attached to the upper end of pistonrod 6 by means of threads 8. The plunger may be unscrewed and replacedby another, if it is desired to change the diameter thereof or in theevent of excessive wear. The plunger is hollow and is provided withwater connections 10 to which flexible water piping 12 may be attached.A relatively slender tube 14 is threaded into the upper end of pistonrod 6 in order to insure circulation of water at the upper end ofplunger D even though the connections 10 are made relatively far downthe plunger so as not to interfere with the upward reciprocationthereof.

The effective water cooling chills the plunger and prevents it fromwelding to the cast metal.

The accessibility of the plunger D, making it readily possible to watercool it, and, if necessary, change it, are advantages obtained as aresult of using separated mechanisms for operating the plunger andthedie. Another advantage is a saving in over-all height of the machine,

' inasmuch as-the strokes of mechanisms E and F are independent, andallowance for one need not be made in the other as is thecase whenconcentric hydraulically operated pistons and cylinders are employed.Complicated systems of bushings. and packing. glands in order to sealthe concentric elements are dispensed with. The

' upward movement of the plunger tends to force the molten metal in thedirection in which it is to flow, instead of in the opposite direction.

When using a bottom plunger, such as the plunger D, difllculty arisesbecause of the formation of a fin at the bottom of the receptacle. Theupper end of the plunger should be given a slight taper, say ten totwenty thousandths of an inch in three inches, so that it may beretracted from the. cup-shaped gate formed during the casting operation.This means that when. the plunger is moved downwardly to the bottom ofthe receptacle there is a clearance of ten to twenty thousandths of aninch present, in which metal will be forced when the plunger isoperated, thereby forming a fin of metal which is tightly wedged betweenthe plunger and the opening at the bottom of the cup in which itreoiprocates. This fin causes excessive wear on the plunger, and thedifficulty is apt to be cumulative inasmuch as the fin'may not beremoved with the gate at each casting operation.

I have found. that this diificulty may be overcome-by moving the plungerdownwardly below the bottom of the receptacle in order to clear and freethe fin so that it is readily removed with the gate. The plunger,however, must be brought to a point near the bottom of the receptacle,before a fresh charge of molten metal is poured therein, and theoperating mechanism E, for the plunger, is therefore designed to makeselectively available three positions or movements of the plunger,upward, in order to displace metal from the cup for casting, downward,below the bottom of the cup, in order to facilitate ejection of thegate,and intermediate, near the bottom of the cup preparatory to filling thesame with molten metal.

In the present arrangement'the effective stroke of piston 4 in cylinder2 is made sufficiently great to move the plunger between the desiredupward and downward positions. In addition, a stop 16 is provided whichis reciprocable in the head of cylinder 2, and which, in its upwardposition, determines the intermediate position of piston 4 andconsequently of the upper end of plunger D. Stop 16 is preferablyactuated by a piston 18 reciprocating in a small auxiliary cylinder 20mounted. directly beneath the head of main cylinder 2. To simplify thevalve mechanism of the machine, the area of piston 18 is made relativelysmall, and is at most a substantial amount less than the effective areaof the upper side of piston 4.. The lower side of auxiliary cylinder 20may then be directly connected through pipes 22, 24, and 26 with asource of compressed fluid here exemplified by the main oil supply pipe28. The upper and lower ends of the main cylinder 2 are connected tovalves in a valve system generally designated G, through pipingindicated by the dotted lines 30 and 32. For the downward position, thepressure on the upper side of piston 4 overcomes the resistance of stop16, while for the intermediate position both ends of main cylinder 2 arepermitted to exhaust, in which case the pressure on the auxiliary piston18 becomes effective.

'Ihethree position operation of plunger D insures that any fin formed atthe bottom of the cup will be removed with the gate. Further precautionis taken to lessen the formation of such a fin in its incipiency, toexplain which, attention is directed to'Figs. 6 and 7. In these figuresit will be observed that the receptacle or cup C is substantially largerin diameter than the plunger D, and that the inner wall of the cup 36 isgenerously tapered in order to facilitate removal of the cup-shapedgate.The bottom of the cup is indicated in Fig. 6 by the dotted line 38. Theposition of the upper end of plunger D during the ejection of thecasting is indicated by the broken line 40,. and this, it will beobserved, is a substantial distance below the bottom of the receptacle.The intermediate position of the plunger D, bringing the upper end vthereof 42 of the plunger is slightly above, say a quarter of an inch,rather than flush with, or below the bottom of the receptacle. Theclearance between the receptacle and the plunger at the bottom of thecup is made relatively slight, say at most a sixteenth of an inch,thereby forming a thin, annular groove 44 around the bottom of the cup.The plunger D is water cooled by connections previously described, andthe cup C is Water cooled by means of an annular jacket 46 surroundingthe cup through which water is circu- .lated by means of connections 48best shown in Fig. 1. The cup and plunger both being at a relatively lowtemperature, molten metal when first poured in the cup is exceedinglyrapidly chilled before it has time to reach the bottom of groove 44.When the plunger is elevated, the previously cooled metal in groove 44tends to effectively prevent the flow of molten metal between theplunger and the wall 50 in which it reciprocates.

The cup illustrated in Fig. 7 is a modified form in which the annulargroove 52 at the bottom of the cup, corresponding to the groove 44 inFig. 6, is tapered to run into the plunger. The groove 52 is of theorder of magnitude of a quarter of an inch in height and a sixteenth ofan inch in width at the top thereof. tion and mode of operation of thisgroove is the same as that already described. It may be mentioned thatsurface tension in the molten metal tends to prevent the groove frominitially filling up, and this is followed by rapid chilling which formsa seal against the subsequent formation of a true fin between theplunger and the bearing surface 50 of the cup.

Reverting now to Fig.1, the mechanism F for opening and closing the diecomprises a cylinder 56 mounted on and supported by a fixed plate 58,here formed integrally with the cylinder 56. Fixed plate 58 is spacedfrom lower fixed plate 60 by pillars 62. In the present machine only twopillars are employed in order to make the die of the machine asaccessible aspossible. The upper die portion B is detachably mounted ona movable plate 64 moved by a piston 66 through "a piston rod 68. Thediameter of piston 66 is selected to obtain sufficient area in excess ofthe area of the lower side of the piston to keep the die portions A andB tightly compressed together during the casting operation in spite ofthe relatively large area of the die which may be subjected to the fullcasting pressure. The total effective force on piston 66 is made safelyin excess of that which may be encountered at the die, in order toprevent or minimize the formation of fins at the parting line of thedie.

The effective area on the lower side of piston 66 is designed to obtainsufficient upward force to elevate the die B and the movable plate 64 towhich it is attached, as well as to operate ejector plate and core platemechanism later described. The diameter of piston rod 68 then works outto be nearly as great as the diameter of piston 66. This constructionpossesses several advantages. In the first place, the volume of oil andconsequently the hydraulic power consumed may be minimized if theeffective area on the lower side of piston 66 is not made excessive. Inthe second place, the difference in area between the upper and lowersides of the piston becomes so great that it is practicable to admitpressure continuously to the lower end of cylinder 56 and to use only asingle valve controlling the fiow of oil to the upper end of thecylinder. The lower end The funcof cylinder 56 is connected to the highpressure pipe 28 through a pipe 70 connected to the pipe 26 previouslyreferred to. The upper end of cylinder 56 is connected through pipe '72with one of the valves in the valve system G.

The valve system G is best shown in Figs. 1, 2, and 9, and comprises avalve box or chest '76 provided with three sets of valves X, Y, and Z.The precise construction of the valve chest and valves may beconventional and forms no part of the present invention. It need only bebriefly mentioned that the valve box is suitably partitioned, and thevalves and piping so interconnected that the pipe 72 may be effectivelyconnected to either the high pressure oil supply pipe 28 or a lowpressure exhaust pipe 78 by operation of valves X; that the pipe 32 maybe effectively connected to either the high pressure oil supply pipe 28or the low pressure exhaust pipe 78 by the valves Y; and similarly, thatthe pipe 30 may be connected to either the high pressure oil supply pipe28 or the low pressure exhaust pipe 78 by the valves Z. The valves X, Y,and Z are respectively operated by cam followers 80, 82, and 84 which inturn are respectively operated by'cams 86, 88, and 90, all mounted on ashaft 92. Shaft 92 carries a sprocket gear 94 interconnected by asprocket chain 96 with a sprocket pinion 98 mounted on a countershaft100. Countershaft 100 may be rotated by either the manually operablecrank 102 or by an electric motor 104 connected to the countershaft 100through pinion 106 meshing with gear 108 carrying sprocket pinion 1 10driving sprocket chain 112 meshing with sprocket gear 114 mounted on thecountershaft 100.

The gear ratio between countershaft 100 and cam and crank shaft 92 ispreferably made a reduction of one to five for the following reason.

The present die casting machine is a five step 115 machine incontradistinction to the ordinary die casting machine which is a fourstep machine. In the ordinary machine the operating steps are:

1. Closing of die.

2. Operation of plunger.

3. Retraction of plunger.

4. Opening of die and ejection of casting.

In the present machine a fifth step is added in order to take care ofmovement of the plunger to the intermediate position near the bottom ofthe receptacle preparatory to filling the latter with molten metal. Thestages in the operation of the present machine are:

1. Closing of die.

2. Operation of plunger upwardly.

3. Retraction of plunger downwardly below the cup.

4. Opening of die and ejection of casting.

5. Movement of plunger to intermediate position, and filling of cup.

The exact time needed between the various operations listed above is avariable, dependent upon the size and complexity of the casting andvarious other factors, and is best determined empirically. By making thegear reduction be tween crank 102 and cam shaft 92 one to five, it ismerely necessary to initially distribute the cams 86, 88, and 90 forequal time between stages, and then torotate crank 102 a single fullrevolution for each stage inthe operation of the machine. If the pieceis to be cast many times, the optimum timing between stages is measured,and the cams are then redistributed on shaft 92 in order to properlyapportion the desired time intervals. The control circuit of elecstoppedautomatically after each casting. In

other cases, continuous operation may be found convenient, and in suchcases the timing between steps five and one, listed in the above table.should, of course, include suflicient time for removal of the ejectedcasting and pouring molten metal into the cup.

Valves X control the pressure applied to the upper end of cylinder 56through pipe 72; valves Y control the pressure applied to the lower endof cylinder 2 through pipe 32; and valves Z control the pressure appliedto the upper end of cylinder 2 through pipe 30. Also, pressure isconstantly applied to the lower end of cylinder 56 and to the lower endof cylinder 20. To obtain the five desired operating stages enumeratedabove, the valves X, Y, and Z are turned to either pressure or exhaustin a manner which is best summarized by the following table, in whichpressure is indicated by P and exhaust is indicated by E.

r V Valves Operating steps X Y Z P E E P P E P E P E E P E E F limits.

Study of this table will readily show that for step 1,- pressure isapplied to the upper end of cylinder 56 in order to close the die. Forstep 2 pressure is then additionally applied to the lower end ofcylinder 2 in order to force the plunger upwardly for the castingoperation. ,In step 3 the pressure at the lower end of cylinder 2 isrelieved and is instead applied to the upper end of cylinder 2 in orderto retract the plunger downwardly to its lowermost position. In step 4the pressure on the. upper end of cylinder 561s relieved, therebypermitting the constant pressure at the lower end thereof to open thedie. Pressure. on the upper end of cylinder 2 is maintained in order tokeep the plunger in its lowermost position during the removal of thecupshaped gate' with the casting. For the fifth step the pressure onthe'upper end of cylinder 2 is relieved. thereby permittng the constantpressure in auxiliary cylinder 20 to move the plunger to itsintermediate position near the bottom of the cup preparatory to fillingthe same.

The size of the die may vary between wide The die open ng needed dependsupon the size of the casting ejected, and in the more usual case ofrelatively small castings, depends upon thespace needed-to manipulatethe ladle for filling the cup. It will be evident that if the die isrelatively small in over-all height, the opening thereof w ll beexcessively great if the piston 66 is permitted to rise to the top ofcylinder 56. Any unnecessary opening of the die causes a direct loss intime and a loss in power due to the wasted volume of high pressure oillater needed to move the piston downwardly for its full stroke.Accordingly, provision is made to limit the opening of the die and theupward stroke of piston 66 to only the necessary amount. To this end,split collars 120 are mounted on pillars 62 at the upper end thereof,and these act as stops for limiting the permissible upward movement ofthe movable plate 64. When the die is changed to oneof difierent height,the split collars 120 may readily be removed and replaced by others ofdifferent dimension in order to compensate for the diiference in diedimension. The same collars might be moved along pillars 62 and lockedbymeans of the bolts provided thereon, but it is thought preferable in thepresent case to rely on the direct stopping action of dificrent sizes ofcollar, rather than the frictional grip of such a collar on the pillar.

In the event of an excessively great change between the fixed plates 58and 60 is made variable. This may be done by unlocking the top andbottom nuts 122 on each of the two pillars 62, elevating the upperportion of the machine F, and replacing the pillars 62 with longer onesbetter adapted to accommodate the new size of die. This type of change,of course, need only be made at rare intervals in order to accommodate acasting of special nature.

, In the present machine the separable die portions A and B arepreferably the cover and ejector die portions, respectively. In otherwords, the die is inverted and operated upside down. This arrangement ispreferred for a number of reasons. To begin with, it is desirable thatthe fixed plate 60, rather than the movable plate 64, be at the bottomof the machine, because this simplifies the direct attachment of thelegs 124 of the frame thereto. In the second place, it permits the cupC, which must be in the lower portion of the die, to remain at a fixedaltitude. Having determined that the fixed plate 60 is to be the lowerplate, it is then desirable to mount the cover die on the lower plate,because movement of the ejector die may. be taken advantage of tooperate the ejector and core plates therein. Also, the cover die isrelatively small, and constant in height, and therefore keeps thealtitude of the cup C substantially constant with relation to the fixedplate 60.

In fact, the cup C, while effectively forming a part of the cover die A,is in reality a separate readily replaceable member mounted directlyupon the fixed plate 60. For this purpose the cup is formed with adepending cylindrical portion 126 (see Figs. 6 and 7) which isaccurately fitted in one of a plurality of stepped openings 128 in thefixed plate 60. The cup-is further provided with a flange 130 which fitsinto and forms the cover of the water jacket 46 which cools the cup. Theuppermost part of the cup 132 is made cylindrical and equal in height tothe thickness of the cover die. The latter is provided with a centralaperture 134 (see Fig. 1) which fits tightly and accurately over theuppermost part of the cup 132 and rests upon the fixed plate 60. It maybe anchored thereto by means of appropriate lugs held by bolts the headsof which'are located in suitable T slots 136. The cover-die A is,whenever possible, designed to have a perfectly flatand plane uppersurface. To this end, the gates and safety for the cup are preferablyformed in the ejector die B. Thus, referring to Fig. '7, the uppersurface 133 of cover die A is left plane, and'passages for the gates135, and for the excess of metal, or safety, 137 at the top of the cupare cut into the ejector die B. p

The ejector die comprises a die proper 188 and a die box 140 housing thenecessary ejector plate 142 and the usually necessary core plate 144.The ejector die is mounted as a unit on the movable plate 64 by means ofappropriate bolts the heads of which may be located in T slots 146.

The operation of the core plate 144 may best be described with referencetoFigs. 1, 4, and 5, in which the core plate 144 is shown to beinterconnected by levers 150 with the upper fixed plate 58 and themovable plate 64 to obtain a movement of the core plate 144 toward coverdie A when the die is closed, in order to insert the cores intoposition, and away from the cover die A when the die is opened, in orderto retract the cores and so to facilitate ejection of the finishedcasting. More specifically the levers 150 are anchored at one end by apin 152 to a fixed member 154 mounted on the fixed frame of the machine.This mounting, in the present case, is made at the upper end of member154 to the fixed plate 58 through bolts 156. The opposite ends of levers150 carry pins 158 rigidly mounted on or formed integrally with the coreplate 144. The levers 150 are mounted at an intermediate point through abearing 160 fixed in a plate 162 mounted on movable plate 64 throughbolts 164. The apertures at the ends of lever 150 are slotted to allowfor angularity of the lever.

When the die is opened, the upward movement of bearing 160 relative tofixed pin 152 causes each lever 150 to swing upwardly in the mannerindicated in Fig. 1. This causes the movable end of lever 150 to movepin 158 and with it the core plate 144 still further upward and so tocause retraction of the cores mounted thereon. When the die is closed.the downward movement of bearing 160 relative to fixed pin 152 causesthe lever 150 to swing downwardly in the manner illustrated in Fig. 4,thereby causing movement of pin 158 and with it the core "plate towardthe cover die A, thereby inserting the cores in proper positonpreparatory to the casting operation. It should be noted that levers 150are preferably run in opposite directions for the sake of symmetry.Adjustment of the desired movement of the core plate may be obtained bymovement. of the plates 162 relative to the movable plate 64. Thus theelevation of the core plate relative to the die may be adjusted bymovement of bearing plates 162 in a vertical direction permitted byslots 166. When a considerable change in amount of movement of the coreplate is needed, the bearing plates 162 may be moved sideways alongmovable plate 64 by transferring the bolts'164 to different ones of thethreaded holes 168.

The ejector plate 142 is provided with a pair of catches or lugs 170.-These are designed to contact with a pair of fixed stops near the end ofthe upward movement of the ejector die, thereby causing a downwardmovement of the ejector plate relative to the ejector die, resulting inthe ejection of the finished casting. In the present case the stops areindicated at 172 and are provided at the upper ends of arms 174 boltedto the lower fixed plate 60 by bolts 1'76. When the die is closed, theejector plate is raised to the proper casting position by means ofsurface or stop pins 180 mounted on the ejector plate 142 and contactingdirectly with the upper face of the cover die A at points notinterfering with the desired mold impressions. The length of the surfacepins 180 is made exactly right so that the ejector pins will be flushwith the surface of the casting during the casting operation. Theejector plate 142 is held against upward movement during the castingoperation by pressure exerted thereon through the levers 150 whichoperate the core plate 144. For this purpose the ends of the core platenearthe pins 158 are provided with stop screws 182 which may be properlyadjusted to bear tightly against the ejector plate when the die isclosed, and this adjustment may be retained by lock nuts 184.

The ejector die, in addition to the usual ejector pins advantageouslyplaced to eject the finished casting, is provided with ejector pins 186for ejecting the cup-shaped gate. These are preferably four in numberand are best shown in Fig. 7. This figure is interesting in showing howthe ejector pins 186 for the gate may be shortened, permitting the metalto be cast in metal risers 188 when difliculty is experienced with.obtaining proper retraction of the cupshaped gate from the receptaclewhen the ejector die is elevated. Shortening of the ejector pins 186provides the risers 188, the surface of which increases the pull of theejector die on the gate.

Occasionally the casting must be provided with a side pulled core. Thisis, whenever possible, located in the ejector die or on the partingline, in which case it is arranged to move with the ejector die. Toobtain automatic operation of such a core, simple apparatus may beattached to the machine in a manner indicated in Fig. 5. A slottedmember 190 is bolted to the fixed frame of the machine, preferably tothe lower fixed plate 60, by means of bolts 192 at a point alongside ofthe necessary core 194. A follower 196 is attached to the core 194 andis arranged to ride in the slot 198. During the opening and closing ofthe ejector die, the follower 196 rides upwardly or downwardly in theslot 198 and consequently is pulled outwardly or moved inwardly, therebyretracting the core 194 when the die is opened, and re-inserting thecore when the die is closed, as is desired.

In rare cases the nature of a complex casting is such that it isnecessary to provide a side pulled core in the cover die. Such a coremay be operated manually, but this is undesirable because a singlemisstep in which the core is not pulled completely out of the castingbefore-the die is opened, will ruin the casting and possibly the die. Inaccordance with the present invention, automatic operation of such acore may readily be provided, by attaching core pulling mechanism,indicated generally at H in Fig. 3, to the machine. This mechanism ispreferably hydraulically operated and is so piped to the remainingelements of the machine that no additional valves, or changes in thevalve mechanism G previously described, are needed, and yet re tractionof the core prior to opening of the die,

and insertion of the core prior to operation of the plunger D are allassured.

In Fig. 3, the cover die A is mounted on the lower fixed plate 60 bymeans of lugs and bolts anchoredin T slots 136. The cover die isprovided with the cup C in the usual manner and may, if necessary, beadditionally provided with passages 200 and mold impressions 202 for thecastings to be made. One such mold impression 20.4 is shown to beprovided with a side pulled core 206. To operate this core a relativelysmall cylinder 208 is temporarily attached by means of a bracket 210 tothe side of plate 60 adjacent the core 206. The cylinder 208 is arrangedwith the cylinder head toward the die, and the piston rod 212 attachedto piston 214 projecting from the end of cylinder 208 opposite the die.The movement of piston rod 212 is transferred to the core 206 by meansof a link 216 surrounding the cylinder. The head of cylinder 208 isconnected through a pipe 218 to the piping 30 and valves Z controllingthe pressure applied to the upper end of plunger operating cylinder 2.The outer end of cylinder 208 is connected through a pipe 220 to thesource of compressed fluid and may be connected with the pipe 28 throughany of the pipes 24, 26, or '70. The effective area of ,the

outer or piston rod side of piston 214 is made sufficient to hold thecore in place against the casting pressure The difference in area of thesides of the piston is made sufficient to pull the core out of thecasting in spite of the constant pressure applied atthe outer side ofthe cylinder.

With this arrangement a moments reflection will show that pressure isapplied to the head of cylinder 208, and the core 206 is retracted whenthe plunger D is moved to its downward position, which is prior to theopening of the die. The pressure in pipe 218 is relieved, and the coreis re-inserted in. place by the pressure constantly applied to pipe 220when plunger D is moved to its intermediate position preparatory tofilling the cup with molten metal which, of course. is prior to closingof the die and upward movement of the plunger. In other words, core 206is inserted at step 5 in the table previously given, and

the core is retracted during steps 3 and 4 in the said table. It shouldbe appreciated that the reversal of cylinder 208 is intended merely toobtain retraction of the core when pressure is applied to the head ofthe cylinder, and that the cylinder may therefore be reversed andinterconnected with the core through a lever or other device forreversing movement, instead of using the exact arrangement heredisclosed.

In Fig. 3 the cup C is-located at the center of the die, and this centergate arrangement is preferable and is ordinarily employed when makingsmall castings which may be distributed around the cup in the die.However, if it is necessary to make a large casting. or a casting ofsuch shape that a center cup will interfere with the mold impression,provisionis made for moving the cup to one side or the other, as may benecessary,

and such an offset or side gate is indicated in Fig. 2. To accomplishthis, the lower fixed plate 60 is provided with a plurality of steppedopenings 128 each capable of receiving the cup C. The hydraulicmechanism E for operating plunger D is transversely reciprocable onrails 222 formed on the inside faces of the legs 124 of the frame.The'piping to the hydraulic mechanism E is provided with appropriateswivel joints 224 so as to accommodate the desired transverse movement.It will be evident that when dealing with a die necessitating a sidegate it is merely necessary to move the cup C from one to the other ofthe stepped openings 128 for receiving the same, and to correspondinglymove the plunger D and the entire hydraulic mechanism E to the importantadvantages of using separated mechanisms E and F for the operation ofthe plunger and the .die, in contrast with the concentric combinedmechanism emplcyed in the machine disclosed in the aforementionedcopending application.

It sometimes is necessary to cast a piece even larger than that whichmay be accommodated with a side gate. This is particularly true if thepiece is relatively long and slender in dimension, so that furtherdifficulty may arise in 0btaining a rapid and effective distribution ofmetal to the remote ends of the casting. In either of these cases theproblem may be solved by utilizing a plurality of receptacles or cupsfor molten metal all gated to the single casting and all com-\ pressedsimultaneously by a plurality of plungers. A special machine may bedevised for this operation, but in the present case it is preferred thatuniversal machines of the type so far described be so made that aplurality of the machines may be locked together and simultaneouslyoperated, when necessary. A plant which cannot afford the overhead of aspecial machine used only at long intervals, may frequently find itprofitable to accept such special orders when it may use the standardmachines already available.

The manner in which two of the machines so far described may be operatedtogether to accommodate large castings is illustrated in Fig. 8. Theouterlegs 124 of the machines are left unchanged, but the inner legs arepreferably removed and replaced by a common leg 230. The cover die A isbolted to the two lower fixed plates 60, while the ejector die B isbolted to the two movable plates 64. The machines may be piped inparallel to a single valve mechanism such as the valve mech-.- anism Gpreviously described. If the machines were located quite closelytogether before being combined so that alteration of the oil pipingbetween each machine and its valve mechanism is not necessary, it may befound preferable to simply gear the valve mechanisms together to insuresynchronous rotation thereof. Withe'ither arrangement the operation ofthe machine will be exactly like that-previously described in connectionwith the single machine, except that when the die is opened tworeceptacles must be filled with molten metal before the next cycleofcasting operation is begun. The castings obtained are improved incharacter due to the improved distribution of metal obtained when aplurality of sources of metal under pressure are 125 provided. i

The mode of constructing and operating the die casting machine of myinvention, and the many advantages thereof will, it is thought. beapparent from the foregoing detailed description thereof. The machineretains the economy of floor space of my prior machine, and yet isgreatly reduced in over-all height. The hydraulic mechanism isremarkably simplified by the use of separated mechanisms for the plungerand die, and water cooling of the plunger is readily provided. Theupwardly movable plunger force's the metal directly toward, instead ofaway from, the gates and mold impressions. The formation of a fin due tothe use of a bottom plunger is minimized, and ejection of the fin isprovided for. Automatic operation of the ejector and core plates of thedie, as well as automatic operation for side pulled cores whether in theejector die or the cover die, are all obtainable. The valve mechanismemployed to control the operation of the machine is relatively simple,insures proper sequence of operation, and accommodates hydraulic corepulling mechanism without added complications. The valve mechanism 150may be manually or power operated, and the manual operation may be usedto determine the optimum apportionment of time between the steps in theoperation of the machine, and this apportionment may be obtained withthe power operation of the valve mechanism. Variations in die height maybe accommodated, and even extreme variations may be handled by replacingthe pillars of the machine. The castings may be made with either acenter or side gate, as may be necessitated by the nature of thecasting, and even extremely large or relatively long and thin castingsmay be manufactured by the use of a multiple plunger machine obtained,if desired, simply by assembling a plurality of single plunger machinesin parallel.

It will be apparent that while I have shown and described my inventionin the preferred forms, many changes and modifications may be made inthe structures disclosed without departing from'the spirit of theinvention, defined in the following claims.

I claim:

1. A die casting machine comprising a receptacle for receivingindividual charges of molten metal to be cast, a mold in communicationtherewith for receiving the bulk of the charge of molten metal, and aplunger located below said receptacle and movable upwardly into thereceptacle for displacing most of the metal from the receptacle into themold, said plunger being substantially smaller in diameter than thediameter of the body of metal in the receptacle and having a clearancebetween itself and the receptacle which at its minimum is substantiallylarger than the maximum normally permitted clearance used between theplunger and cylinder of die casting machines generally.

2. A die casting machine comprising separable die portions including adownwardly tapered receptacle for molten metal to be cast and a mold incommunication therewith, a plunger located below the receptacle andmovable upwardly into the receptacle for displacing the metal upwardlyfrom the receptacle into the mold, said plunger being smaller indiameter than the diameter of the body of metal in the receptacle,plunger operating means located below the die portionsv and receptaclefor reciprocating said plunger, and means for ejecting the resultingcasting and together with it the solidified residue when the dieportions are separated.

3. A die 'casting machine comprising a receptacle for molten metal to becast, a mold in communication therewith, a plunger movable upwardly intothe receptacle for displacing the metal from the receptacle into themold, said plunger being smaller in diameter than the diameter of thereceptacle, and means to position the plunger slightly above the bottomof the receptacle, the bottom of said receptacle being tapered towardthe side of the plunger.

4. A die casting machine comprising a' receptacle for molten metal to becast, a mold in communication therewith, a plunger substantially smallerin diameter than the diameter of the body of metal in the receptacle andreciprocable therein to force metal from the receptacle into the mold,and means for selectively moving the plunger to any of three positionsrelative to said cooperating receptacle, the intermediate positionpermitting filling of the receptacle.

in said receptacle, means for reciprocating the upper end of saidplunger upwardly into the receptacle and downwardly below thereceptacle, and means for stationarily positioning the upper end of saidplunger near the bottom of the receptacle when filling the receptaclewith molten metal.

6. A die casting machine, comprising a receptacle for molten metal to becast, a mold in communication therewith, a plunger substantially smallerin diameter than the diameter of the metal in the receptacle, means forpositioning the upper end of said plunger near the bottom of thereceptacle when filling the receptacle with molten metal, means to forcethe upper end of the plunger upwardly into the receptacle for dis.

placing the metal from the receptacle into the mold, and means forretracting the upper end of the plunger downwardly to a point asubstantial distance below the bottom of the receptacle to facilitateejection of the gate.

7. A die casting machine comprising a receptacle for molten metal to becast, a mold in communication therewith, a plunger substantially smallerin diameter than the diameter of the body of metal in the receptacle andreciprocable therein to force metal from the receptacle into the mold, acylinder and hydraulically operated piston for moving the plungerbetween upward and downward positions, and means for stationarilypositioning the piston and plunger at an intermediate position to permitfilling of. the receptacle.

8. A die casting machine comprising a receptacle for molten metal to becast, a mold in communication therewith, a plunger reciprocable in saidreceptacle, a cylinder and hydraulically operated piston for moving theupper end of the plunger between an upward position for forcing metalfrom the receptacle into the mold and a downward position for retractingthe upper end of the plunger from the receptacle preparatory to ejectingthe solidified residue from the receptacle, and additional means formoving the piston and the upper end of the plunger from the lowermostposition to an intermediate'position near the bottom of the receptaclepreparatory to filling the receptacle with molten metal.

9. A die casting machine comprising a receptacle for molten metal to becast, a mold in communication therewith, a plunger smaller in diameterthan the diameter of the receptacle, a cylinder and hydraulicallyoperated piston for moving the plunger between an upward position forforcing metal from the receptacle into the mold and a downward positionfor retracting the plunger from the receptacle preparatory to ejectingthe cup-shaped gate from the receptacle, an auxiliary cylinder andhydraulically operated piston located beneath the head of the aforesaidcylinder, and a stop operated thereby for moving the plunger from thelowermost position to an intermediate position slightly above the bottomof the receptacle preparatory to'filling the receptacle with moltenmetal.

10'. A die casting machine comprising a receptacle for molten metal tobe cast, a mold in communication therewith, a plunger smaller indiameter than the diameter of the receptacle, a

main cylinder and hydraulically operated. piston i.

for moving the plunger between an upward casting position and a downwardposition below the receptacle, a relatively small auxiliary cylinder andpiston, a stop operateckthereby for moving the plunger from the downwardposition to an v 1,96l,94-2 intermediate filling position, a sourcelofcom pressed fluid, means always connecting said source to the auxiliarycylinder, and valve means for selectively connecting either side of themain cylinder to' said source or to exhaust.

11. A die casting machine comprising relatively movable heads adapted toreceive any of a number of dies having a mold impression and acooperating receptacle for molten metal, a reciprocable plungersubstantially smaller in diameter than the body of metal to be containedin the receptacle for displacing metal from said receptacle into themold impression, mounting means adjustable to permit transverse movementof the plunger toward one side or the other of the die-carrying heads inorder that the receptacle may be differently located in the severaldies, as convenience may dictate, and means to operate the plunger.

12. A die casting machine comprising a lower fixedplate provided withsupporting means for supporting a receptacle for molten metal in any ofa plurality of locations on said plate, a die supported by said plate, amold impression in said die, a receptacle for molten metal supported bysaid fixedplate and projecting upwardly into said die, an upwardlyreciprocable plunger substantially smaller in diameter than the body ofmetal in the receptacle for displacing metal from said receptacle intothe mold, means lo cated beneath said fixed plate for operating saidplunger, and mounting means adjustable to permit movement of thereceptacle, plunger, and operating means therefor toward one side or theother of the fixed plate in order that the plunger may be mated with thereceptacle when the latter is located as desired.

18. A die casting machine comprising spaced fixed plates, pillars.therebetween determining the separation of the plates, a die portionmounted on one of said plates, a hydraulically operated piston andcylinder mounted onthe otherof said plates, a movable plate operatedthereby, a die portion mounted on said movable plate for movement towardand from the aforesaid die portion, and adjustable means for limitingthe opening movement of the piston and movable plate to a desiredminimum value dependent upon the particular die used in the machine.

14. A die casting machine comprising lower and upper fixed plates,replaceable pillars therebetween determining the separation of the fixedplates, a cover die and a. receptacle for molten metal-supported by thelower plate, an upward 1y reciprocable plunger substantially smaller indiameter than the body of metal in the receptacle and a hydraulicallyoperated piston and cylinder connected thereto and located beneath thefixed plate for displacing metal from the receptacle, a hydraulicallyoperated piston and cylinder mounted on the upper fixed plate, a movableplate operated thereby, an ejector die mounted on said movable plate formovement toward and from the cover die, and adjustable means forlimiting the upward movement of the movable plate and upper piston to adesired minimum value dependent upon the particular die used in themachine. I

15. A die casting machine comprising a lower fixed plate, a' die and areceptacle for molten metal supported thereby, an upwardly recipro- 1cable plunger for displacing metal from the 1'67 ceptacle, hydraulicallyoperated piston and cylinthe receptacle into the mold, a downwardposition below the receptacle preparatory to ejecting the cup-shapedgate, and an intermediate position near the bottom of the receptaclepreparatory to filling the receptacle with molten metal, an uppermovable plate, a die supported thereby, hydraulically operated pistonand cylinder mechanism for moving the movable plate in order vto open orclose the die, a source of compressed fluid, and valve means soconnecting said source with the said mechanism as to cause closing ofthe die prior to the casting movement of the plunger, and movement ofthe plunger to the intermediate position prior to closing of the die.

16. A die casting machine comprising a lower fixed plate, a cover dieand a receptacle for molten metal supported thereby, an upwardlyreci'procable plunger for displacing metal from f plate, a source ofcompressed fluid, and valve means so connecting said source with thesaid mechanism as to cause closing of the die prior to the castingmovement of the plunger, retraction of the plunger prior to opening ofthe die, and movement of the plunger to the intermediate position priorto closing of the die.

1'7. A die casting machine comprising a fixed frame, a movable plate, anejector die attached thereto, a core plate in said ejector die, aplurality of levers so interconnecting the fixed frame, the movableplate, and the core plate that the core plate is moved toward theparting face of the die when the die is closed and away from the partingface of the die when the die is opened, and means associated with saidlevers for adjusting the movement of the complete relative to themovement of the ejector die.

18. A die casting machine comprising a fixed frame, a movable plate, anejector die attached thereto, a core plate in said ejector die, and alever having one end pivoted on the fixed frame, the other end pivotedon the core plate, and an intermediate point pivoted on the movableplate, so that the core plate is moved toward the parting from theparting face of the die when the die is opened.

19. A die casting machine comprising a frame including fixed upperandlower plates and pillars separating the same, a movable platetherebetween, a cover, die and a receptacle for metal to be cast mountedon the lower fixed plate, an upwardly reciprocable plunger substantiallysmaller in diameter than the body of metal in the receptacle fordisplacing metal therefrom, an ejector die attached to the movableplate, a core plate in said ejector die, and a plurality of levers sointerconnecting the fixed frame, the movable plate, and the-core platethat the core plate is moved toward the cover die when the die is closedand away from the cover die when the die is opened.

20. A die casting machine comprising a lower fixed plate, a die and areceptacle for molten metal supported thereby,\an upwardlyreciprocableplunger for displacing metal from the receptacle, a cylinderand a hydraulically operated piston for moving the plunger upward forcasting and downward below the receptacle preparatory to ejection, anauxiliary cylinder and piston, a stop operated thereby for moving theplunger to an intermediate position, a side pulled core in said die, acylinder and piston attached to the fixed plate for operating said core,a source of compressed fluid, means connecting said source with theauxiliary cylinder and one side of the core pulling cylinder, a valvecontrolling the flow of fluid beneath the plunger piston, and a singlevalve controlling the flow of fluid above the plunger piston and to theother end of the core pulling cylinder.

21. A die casting machine for producing sound castings of large or/andelongated configuration comprising a plurality of separable die castingmachines each having a fixed plate, a receptacle for molten metal, areciprocable plunger for displacing metal from the receptacle,hydraulically operated piston and cylinder mechanism for moving theplunger, a movable plate, hydraulically operated piston and cylindermechanism for moving the same, means for rigidly locking said pluralityof machines together, a single die mounted on the fixed plates, a singledie mounted on the movable plates, a source of compressed fluid, andvalve mechanism for connecting said source to similar elements of thehydraulically operated mechanism of the component machines in parallel,in order to cause simultaneous opera-.

tion of the machines as a unit. I

22. A die casting machine for producing sound castings of large or/andelongated configuration comprising a plurality of separable die castingmachines each having lower and upper fixed plates with pillarstherebetween determining the separation thereof, a receptacle for moltenmetal supported by the lower plate, an upwardly reciprocable plungersubstantially smaller in diameter than the body of metal in thereceptacle for displacing metal from the receptacle, hydraulicallyoperated piston and cylinder mechanism formoving'the plunger,hydraulically operated piston and cylinder mechanism mounted on theupper fixed plate, and a movable plate operated thereby, means forrigidly locking said plurality of machines together, a single cover diemounted on the fixed lower plates, a single ejector die mounted on themovable plates, a source of compressed fluid, and valve mechanism forconnecting said source to similar elements of the hydraulically operatedmechanism of the component machines in parallel, in order to causesimultaneous operation of the machines as a unit.

23. A die casting machine comprising a receptacle for molten metal to becast, a mold in communication therewith, a plunger substantially smallerin diameter than the diameter of the body of metal in the receptacle,means for positioning the upper end of said plunger slightly above thebottom of the receptacle when filling the receptacle with molten metal,and means to force the plunger upwardly into the receptacle fordisplacing the metal from the receptacle into the mold.

24. A die casting machine comprising a plate having an opening, areceptacle for molten metal received and supported in said opening withthe upper portion of said receptacle projecting above the plate, a lowerdie portion supported by said fixed plate and fitting the upwardlyprojecting portion of the receptacle, an'upper die portion, and areciprocable plunger for displacing metal from the receptacle into themold portion of the die, whereby the plunger travels in a smoothcontinuous wall unbroken by transverse seams.

25. A die casting machine comprising a plate having a cylindricalopening, a generally cylindrical receptacle for molten metal receivedand supported in said opening with the upper portion of said receptacleprojecting above the plate, a die supported by said fixed plate andhaving an opening for receiving the upwardly projecting portion of thereceptacle, an upwardly reciprocable plunger substantially smaller indiameter than the diameter of the receptacle located subjacent thereceptacle for displacing metal upwardly therefrom into the mold portionof the die, and means for operating said plunger.

26. A die casting machine comprising a lower fixed plate, a diesupported thereby, a downwardly tapered receptacle for molten metal insaid die, an upwardly reciprocable plunger substantially smaller indiameter than the metal in the receptacle for displacing metal from saidreceptacle, a hydraulically operated piston and cylinder located.beneath the fixed plate for opel'ating said plunger, a movable platelocated above the fixed plate, a die mating with the aforesaid diemounted on said movable plate, a hydraulically operated piston andcylinder located above the movable plate for causing movement of thesame in order to open or close the die, a source of fluid medium underpressure, a plurality of valves for controlling the fiow of said mediumto the hydraulic mechanism, a cam shaft provided with a plurality ofindividually adjustably timed cams for operating said valves, and amotor for driving the cam shaft for a complete cycle of operation of thedie casting machine.

27. A large die casting machine comprising a separable plurality ofindividual small die casting machines each having a lower fixed plate, areceptacle for molten metal, an upwardly reciprocable plunger locatedsubjacent said receptacle for displacing metal from the receptacle, anda movable plate located above the fixed plate, a die comprising a singlestationary portion mounted on all of the aforesaid lower fixed plates,and a single mating movable portion mounted on all of the aforesaidmovable plates, means for causing simultaneous operation of saidplungers, and means for causing simultaneous movement of said movableplates.

28. A large die casting machine comprising a separable plurality ofindividual small die casting machines each having a lower fixed plate, adownwardly tapered receptacle for molten metal, a reciprocable plungersubstantially smaller in diameter than the body of metal in thereceptacle for displacing metal from said receptacle, means to operatesaid plunger, a movable plate located above the fixed plate, and meansfor moving said movable plate, a die comprising a single lowerstationary portion mounted on all of the aforesaid fixed plates, and asingle mating movable portion mounted on all of said movable plates, andmeans for causing simultaneous operation of the plungers andsimultaneous movement of the movable plates.

CHARLES PACK.

